Emerson MRLDS-450 User manual

Document Part # 026-4417 Rev 1 Page 1 of 9
©2020 Emerson Retail Solutions, Inc. This document may be photocopied for personal use.
Visit our website at http://www.emerson.com for the latest technical documentation and updates.
The MRLDS-450 refrigerant gas detector is designed for use in refrigeration
applications and may be used as a stand-alone device, or connected to a facility’s
building management system (BMS). It enables compliance with refrigerant
safety codes (ASHRAE 15 and EN378) and features audible and visual alarms to
alert personnel in the event of a refrigerant leak.
1. Safety Instructions
DANGER: The MRLDS-450 is NOT certified or approved for operation in
oxygen-enriched atmospheres. Failure to comply may result in severe injury or
death.
WARNING: Use this product ONLY for the purposes and under the conditions
listed in the user manual. Failure to comply may result in injury and/or damage
to the product. The MRLDS-450 has not been designed to be intrinsically safe
for use in areas classified as being hazardous locations. For your safety, DO NOT use in
hazardous locations. Consult a qualified professional before connecting the MRLDS-450 to devices not mentioned in
this manual. Failure to comply may result in injury and/or damage to the product.
WARNING: The gas diffusion path can become occluded (moisture, dust, debris, frozen condensation) over time, resulting in
reduced or complete lack of gas detection and alarming function. Routine visual inspection of the gas detector and bump
testing are recommended to ensure proper gas detection and alarm function. For information on calibrating the sensor, refer to
the Care and Maintenance section of the MRLDS-450 User Manual P/N 026-1316.
CAUTION: Except for the maintenance detailed in this manual, this product should ONLY be opened and/or
serviced by authorized personnel. Failure to comply may void the warranty.
CODE COMPLIANCE: Comply with all local and national laws, rules and regulations associated with this equipment. Operators
should be aware of the regulations and standards in their industry/locality for the operation of the MRLDS-450.
TECHNICIAN USE ONLY: The MRLDS-450 must be installed by a suitably qualified technician who will install this unit in
accordance with these instructions and the standards in their particular industry/locality. This document is only intended as a
guide and the manufacturer bears no responsibility for the installation or operation of this unit. Failure to install and operate the
unit in accordance with these instructions and with industry guidelines may cause serious injury or death and the manufacturer
will not be held responsible in this regard.
Figure 1 - Refrigerant Gas Detector
Quick Start Guide
Refrigerant Gas Detector (MRLDS-450)
for Machinery Rooms, Cold Rooms and Freezers

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2. Component Overview
# Component Description
1M16 Cable Glands (x6)
2Rubber Gasket
3Internal Alarm Buzzer
4Power Connections (x2)
5Digital Connection (Modbus)
6Analog Connection
7Tactile Switch #1
8Ribbon Cable Connection (To Sensor)
9Tactile Switch #2
10 Relay 3 Connection (FAULT)
11 Relay 2 Connection (HIGH)
12 Relay 1 Connection (LOW)
13 Magnetic (Mag) Switch #1
14 Magnetic (Mag) Switch #2
15 M20 Cable Glands (x2)
Table 1 - Component Descriptions
Figure 2 - Component Locations

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3. Product Specifications
4. Installation
IMPORTANT: The manufacturer of this product requires that a bump test or calibration be performed following
installation to verify installation to verify instrument functionality.
STEP 1: Mount Gas Detector & Remove Lid
CAUTION: DO NOT allow the lid/sensor to hang from the ribbon cable. Failure to comply may result in damage to the product.
1. Mount the MRLDS-450 according to the product dimensions, maximum wiring lengths, and following
considerations:
•Environment: the full range of environmental conditions when selecting a location.
•Application: the specifics of the application (possible leaks, air movement/draft, etc.) when selecting
a location.
Size (HxWxD) 6.5” x 6.5” x 3.4” (165 x 165x 87 mm)
Weight 1.05 lbs (480g)
Indicators Multi-color Status LED
Internal Alarm Buzzer: 72dB @ 3.9” (10 cm)
Alarm Delay Configurable (0 to 15 minutes)
Inputs Tactile Switches (x2), Magnetic Switches (x2)
Outputs Analog Output: 4 to 20mA (default), 0 to 5V, 0 to 10V, 1 to 5V or 2 to 10V
Bluetooth® Bluetooth® Low Energy, BLE 4.2
Modbus Connection: RS-485 terminal block
Baud Rate: 9,600 or 19,200 (default)
Data Bits: 8
Parity: None, Odd, or Even (default)
Stop Bits: 1 (default) or 2
Retry Time: 500 ms (minimum)
Power Supply 19.5 to 28.5 VDC or 24 VAC ±20%; 4W
Wiring (Power) 2-core cable, 16 to 28 AWG
Wiring (Relays) 2-core cable, 16 to 28 AWG
Wiring (Modbus) Recommended: Belden 3106A (or equivalent) 3-core, 2 twisted pair +
ground, shielded cable with 120 Ωcharacteristic impedance,
16 to 28 AWG
Enclosure Material: ABS
Protection: IP66
Temperature Semiconductor: -40°F to 122°F (-40°C to 50°C)
Electrochemical: Ranges vary by gas type and / or concentration,
see the MRLDS-450 user manual (P/N 026-1316) for a full list of
temperature ranges.
Infrared: -40°F to 122°F (-40°C to 50°C)
Catalytic Bead: -40 to 122°F (-40°C to 50°C)
Humidity 5 to 90% RH, non-condensing
Pressure 23.6 to 32.5”Hg (800 to 1,100 mbar)
Elevation 0 to 6,560’ (3,000 m) altitude
Table 2 - Product Specifications

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•Accessibility: the degree of accessibility required for maintenance purposes when selecting a location.
•Target Gas: the specific gravity of the target gas when selecting the height of the instrument.
2. Using a 5/32” (4mm) hex key/allen wrench (not included), remove the lid and disconnect the ribbon cable from the base.
3. Set the lid and rubber gasket aside to be reinstalled later.
STEP 2: Wire Connections
WARNING: Ensure that all wiring connections are made BEFORE applying power.
WARNING: Relays are rated for 0 to 30V. DO NOT apply main power onto these relays.
IMPORTANT: Cable glands are meant to accommodate one cable. DO NOT use cable glands for more than one cable.
IMPORTANT: If analog output is 4 to 20mA, connect or short the connection to ensure the gas detector does not go into fault.
*IMPORTANT: The MRLDS-450 has a jumper on the analog output. This jumper MUST be removed to use the analog 4-20mA
output signal. If the jumper is removed AND the 4-20mA output signal is not used, the unit will go into fault (refer to the
026-4421 Technical Bulletin for more information).
1. Locate connections (Power, Analog, Modbus, Relays) and remove terminal blocks from the PCBA.
2. Remove plugs from the corresponding M16 cable glands and pass the cable through the opening.
3. Secure wires in each terminal block and, pressing firmly, reinstall the terminal block in the PCBA.
4. Remove all excess cable from the housing before firmly securing the cable glands.
STEP 3: Reinstall Sensor and Connect Lid
CAUTION: DO NOT leave excess cable inside of the gas detector housing. Failure to comply may result in damage to the product.
IMPORTANT: To achieve proper seal in the IP66 enclosure, the lid screws should be torqued to 15 to 20 lbf in (1.5 to 2.0 Nm).
1. Reinstall the rubber gasket. Ensure that it is correctly seated by placing the side with two grooves face down and the edge
with two bumps on the top.
Figure 3 - Locate Connections
Figure 4 - Rubber Gasket Placement

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2. Reconnect the ribbon cable from the sensor to the PCBA as shown:
3. Ensure no cables are interfering with the sensor module and close the lid.
4. Using a 5/32” (4 mm) hex key/allen wrench, tighten the lid screws in an Xtightening pattern:
5. MRLDS-450 Network Setup for Site Supervisor and E2
For Modbus end-of-line termination, use 150Ωohm resistor or termination block P/N 537-2711. Do not use MRLDS 120Ωohm
on-board termination with Site Supervisor or E2.
IMPORTANT:
• For 24 VAC installations sharing a transformer in a daisy-chain configuration, the neutral polarity must be
maintained for all instruments.
• 24 VAC power polarity must not be reversed.
• For a more robust system, a dedicated transformer for each MRLDS is recommended to prevent damage
caused by wiring errors.
• Fasten terminal screws.
Figure 5 - Ribbon Cable
Figure 6 - Tightening Pattern

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5a. Site Supervisor Device and COMM Setup
Figure 7 - Site Supervisor Setup

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5b. E2 Device and COMM Setup
Figure 8 - E2 Setup

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6. Connect MRLDS-450 to MRLDS-400 Series App (User Discretion)
The MRLDS-450 uses a smartphone application to allow users to interface with the gas detector.
IMPORTANT: Default alias, passkey, and unlock code can be changed via the MRLDS-400 Series App’s configuration menu.
1. Enable Bluetooth® discovery by tapping MAG#1 for 1 second. (After 10 seconds, the device will indicate that it is
discoverable with audible heartbeat until it has been paired, discovery has timed-out or has been canceled.)
2. Launch the MRLDS-400 App and click the Bluetooth® icon at the bottom of the screen to initiate a scan.
3. Select the instrument (default is 18TMAE) from the list of available gas detectors.
4. When prompted, enter the passkey (default is 123456).
5. Go to Configure tab to set up the device. When prompted, enter unlock code to access device configuration
(default is 1234).
6. Operation Overview
# APP DESCRIPTION
1 Main Menu (App Settings)
2 Status (Gas Concentration)
3 Calibrate (Calibration/Bump Test)
4 Details (Instrument Information)
5 Disconnect Bluetooth®
6 Restart Connected Device
7 Test Mode (LED/Buzzer/Relays/Analog
Output)
8 Device Configuration
9 Logs
Table 3 - App Description
OUTPUT
STATE LED RELAY 1 RELAY 2 RELAY 3 Buzzer
Warm-up OFF OFF OFF
Normal OFF OFF OFF
Low Alarm ON OFF OFF
High Alarm ON ON OFF
Offline OFF OFF OFF
Fault OFF OFF ON
Negative Gas Fault OFF OFF ON
Zero Cal. Fault OFF OFF OFF
Special Cal. Fault OFF OFF OFF
Table 4 - Outputs
Figure 9 - App

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The contents of this publication are presented for informational purposes only and they are not to be construed as warranties or guarantees, express or implied, regarding the products or services described herein or their use or
applicability. Emerson Retail Solutions, Inc. and/or its affiliates (collectively “Emerson”), reserves the right to modify the designs or specifications of such products at any time without notice. Emerson does not assume
responsibility for the selection, use or maintenance of any product. Responsibility for proper selection, use and maintenance of any product remains solely with the purchaser and end-user.
Document Part # 026-4417 Rev 1 Page 9 of 9
7. Part Number and Ordering Information
Scan the QR code to download the full user manual P/N 026-1316.
*Refer to the 026-4421 Technical Bulletin for more information.
For Technical Support call 770-425-2724 or email
[e-mail]
Emerson P/N
IP66, 3 x Relays, Analog
Output, Modbus Output,
Audible & Visual Alarms
Sensor
Type Emerson P/N Replacement Sensor Sensor Type
Gas Type and Detection Range Pre-calibrated Sensor Modules
809-1040 CO2 0-5,000ppm IR 809-1140 CO2 0-5,000ppm IR
809-1041 CO2 0-10,000ppm IR 809-1141 CO2 0-10,000ppm IR
809-1047 R404A 0-1,000ppm SC 809-1147 R404A 0-1,000ppm SC
809-1048 R407A 0-1,000ppm SC 809-1148 R407A 0-1,000ppm SC
809-1050 R22 0-1,000ppm SC 809-1150 R22 0-1,000ppm SC
809-1056 R448A 0-1,000ppm SC 809-1156 R448A 0-1,000ppm SC
809-1066 R422D 0-1,000ppm SC 809-1166 R422D 0-1,000ppm SC
809-1068 R449A 0-1,000ppm SC 809-1168 R449A 0-1,000ppm SC
MRLDS-450 Accessories
809-1190 Calibration Adapter Kit
809-1191 Horn + strobe 24VDC; blue lens
809-1192 Horn + strobe 24VDC; amber lens
809-1193 Horn + strobe 24VDC; red lens
809-1194 Horn + strobe; blue lens; MP120K 120VAC adapter
809-1195 Horn + strobe; amber lens; MP120K 120VAC adapter
809-1196 Horn + strobe; red lens; MP120K 120VAC adapter
Table 5 - Product Ordering Information